Japanese Patent No. 3867107 discloses a method of using a pulse laser beam for dicing of a semiconductor substrate. This method of Japanese Patent No. 3867107 forms an altered region inside a work piece by means of an optical damage produced by a pulse laser beam. Further, the work piece is cut based on this altered region.
According to a conventional technique, formation of the altered region is controlled using, for example, energy of a pulse laser beam, a spot diameter and a relative movement speed of the pulse laser beam and a work piece as parameters.
Dicing is required to provide high linearity at a cut portion. When, for example, a cut portion is cut only into a zig-zag shape, dicing influences semiconductor devices formed on a work piece, and device performance deteriorates and wide widths of dicing lines need to be secured, and therefore there is a problem that the number of devices which can be formed on a substrate decreases.